Tubes having welded metal baffles on their interior surface are commonly used as heat exchange members in boilers, water heaters, and in other heat exchange devices. Prior apparatus for welding such baffle pieces within a tube is shown in U.S. Pat. Nos 3,600,548 and 4,239,953 to Bock. The machines disclosed therein include an elongated electrode arm that is cantilever mounted to and insulated from a mounting member at one of its ends. The arm is made up of a material having high electrical conductivity and has a welding head mounted on its free end. The baffle pieces are delivered to the desired positions for welding on the interior of the tubing by a sequence of mechanical conveyances that are integrated with the electrode arm. The baffle pieces are dispensed from a chute onto a feed track. The baffle pieces are pushed along the feed track in single file by a baffle pusher which is driven by a spring retracted air cylinder. As each piece reaches the end of the feed track, an assembly commonly called a slicer displaces the lead piece out of the single file line so that it falls into position in front of a pusher lug. The baffle pieces are then driven forwardly by a pusher lug which is driven by a reciprocally acting air cylinder. The pusher lug advances the baffle pieces up a ramp to a position where the baffle pieces are clamped in place against the inside of the tubing by a hydraulic cylinder, and the welding process is commenced. The process is then repeated for each successive baffle piece on the feed track.
Difficulties can result from the method of baffle conveyance described above at the point where the slicer displaces the baffle pieces. In pushing the leading baffle piece so as to fall in an uncontrolled manner in front of the pusher lug, the baffle pieces do not always lie flat at the end of their fall. This interferes with the forward motion of the pusher, and often results in production delays that are necessary to rectify the problem.